实验scrollTo、scrollBy、getScrollX、getScrollY这4个方法的含义

package com.qin.scrollerview; import android.app.Activity; import android.content.Context; import android.graphics.Color; import android.os.Bundle; import android.util.AttributeSet; import android.util.Log; import android.view.View; import android.view.ViewGroup; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.TextView; //自定义ViewGroup ， 包含了三个LinearLayout控件，存放在不同的布局位置，通过scrollBy或者scrollTo方法切换 public class MultiViewGroup extends ViewGroup { private Context mContext; private static String TAG = "MultiViewGroup"; public MultiViewGroup(Context context) { super(context); mContext = context; init(); } public MultiViewGroup(Context context, AttributeSet attrs) { super(context, attrs); Log.i(TAG, "MultiViewGroup ：getWidth()=" + getWidth()+","+"getHeight()="+getHeight()); mContext = context; init(); } private void init() { // 初始化3个 LinearLayout控件 LinearLayout oneLL = new LinearLayout(mContext); oneLL.setBackgroundColor(Color.RED); addView(oneLL); LinearLayout twoLL = new LinearLayout(mContext); twoLL.setBackgroundColor(Color.YELLOW); addView(twoLL); LinearLayout threeLL = new LinearLayout(mContext); threeLL.setBackgroundColor(Color.BLUE); addView(threeLL); } // measure过程 @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { Log.i(TAG, "--- start onMeasure --"); // 设置该ViewGroup的大小 int width = MeasureSpec.getSize(widthMeasureSpec); int height = MeasureSpec.getSize(heightMeasureSpec); setMeasuredDimension(width, height); int childCount = getChildCount(); Log.i(TAG, "--- onMeasure childCount is -->" + childCount); Log.i(TAG, "width=" + width+","+"height="+height); Log.i(TAG, "onMeasure ：getWidth()=" + getWidth()+","+"getHeight()="+getHeight()); for (int i = 0; i < childCount; i++) { View child = getChildAt(i); // 设置每个子视图的大小 ， 即全屏 child.measure(MultiScreenActivity.screenWidth, MultiScreenActivity.scrrenHeight); } } // layout过程 @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { // TODO Auto-generated method stub Log.i(TAG, "--- start onLayout --"); int startLeft = 0; // 每个子视图的起始布局坐标 int startTop = 10; // 间距设置为10px 相当于 android：marginTop= "10px" int childCount = getChildCount(); Log.i(TAG, "--- onLayout childCount is -->" + childCount); Log.i(TAG, "onLayout ：getWidth()=" + getWidth()+","+"getHeight()="+getHeight()); for (int i = 0; i < childCount; i++) { View child = getChildAt(i); child.layout(startLeft, startTop, startLeft + MultiScreenActivity.screenWidth, startTop + MultiScreenActivity.scrrenHeight); startLeft = startLeft + MultiScreenActivity.screenWidth ; //校准每个子View的起始布局位置 //三个子视图的在屏幕中的分布如下 [0 , 320] / [320,640] / [640,960] } } }